09/03/2009
Currently, the standard ethanol blend in the larger U.S. cities is 10%
ethanol to 90% gasoline. Originally, ethanol’s market grew because it
was used as a replacement of MTBE, which is a natural gas-derived
oxygenator that came about to enhance unleaded gasoline. When lead was
removed from gasoline, an oxygenator was required and MTBE was the
first choice. Unfortunately, MTBE is a modified methane hydrocarbon
that has an extra atom of oxygen attached to the molecule. As a result,
MTBE molecules bond with water. Therefore, if there were leakage at a
gas station, the hydrocarbons which float on the top of the water would
actually bond with the water and potentially cause severe health
problems, including certain forms of cancer. Thus, the oil industry was
forced to accept ethanol as an oxygenator to replace MTBE. Over the
years that became an accepted practice. But the ethanol industry,
particularly when the renewables industry started heating up again in
2006, wanted more. The compromise was to create the concept of E85—85%
ethanol / 15% gasoline.